My main rig has been suffering from very random complete freezes over the past month, which require a hard reset. And I can't for the life of me figure it out. Here are the facts: It only does it when the GPU and CPU are under a lot of load(i.e. Folding) It does it rather often while playing Plants vs. Zombies, which is probably due to the high GPU/CPU load. It does it with everything at stock speeds. When I reboot the computer after the freeze. All of the websites that I've logged into, such as TPU, require me to log in again. <-- This one is really strange to me. PSU fan has started to noticeably click when I shut the computer down, but I know it is still spinning, but maybe not fast enough? Here is what I've tried: Reset everything to stock. Swapped out 3 different video cards. Ran CPU folding only for a week. <-- No freezes. Ran GPU folding only for a week. <-- No freezes. Added second auxilary PSU to power GPU only. Removed 2 sticks of RAM. That is kind of where I'm stumped. I thought maybe it was the PSU, so I tried to take some load off of it by adding an auxilary PSU I had laying around. That didn't help at all, though I still think it might be the PSU, so I ordered a Corsair HX850, which should be here this week. The PSU is almost 3 years old at this point. My next guess is the HDD, and I only say that because it seems like every time the computer freezes, it corrupts any cookies I have stored, forcing me to log into every website again. Also, it is probably older than the PSU at this point. If the new PSU doesn't fix it, a new HDD is probably my next step. I also found it very stange that it crashes a lot with Plants vs. Zombies(girlfriend loves it, which pisses her off more than me, but gets me in trouble every time it freezes just as she is about to win a level). However, I figured out that even though it is a very simple game graphically, it uses a lot of CPU and GPU power(it is hardware accellerated and does use a lot of the CPU when there is a lot of stuff going on). I haven't had a freeze in any other game, including Just Cause 2, which I've been playing extensively. Am I overlooking anything?